The　GaN　epitaxial　wafers　with　a　p-GaN　surface　are　irradiated　with　an　excimer　laser　at　different　energy　densities　and　pulse　numbers.　The　laser　irradiation　induced　changes　in　optical　and　electrical　properties　of　GaN　epitaxial　wafers　are　examined　using　photoluminescence,　cathode　luminescence,　X-ray　photoelectron　spectroscopy,　Hall,　I-Vcharacterization.　Experimental　results　show　that　under　an　appropriate　laser　irradiating　condition　and　annealing　treatment　in　N2,　the　luminescent　and　electrical　properties　of　the　samples　are　improved　to　different　degrees.　The　irradiated　and　annealed　samples　are　transformed　into　light　emitting　diode　(LED)　device　with　semiconductor　packing　process,　and　the　relationship　between　the　luminescent　properties　of　LED　and　the　laser　energy　density　or　annealing　atmosphere　are　investigated.　After　laser　irradiaiton　and　annealing　treatment,　the　light　output　power　of　GaN-based　LED　increases　at　least　about　37%　compared　with　non-irradiated　samples,　which　shows　that　the　improvement　of　the　electrical　properties　of　GaN　epitaxial　materials　plays　important　role　in　enhancing　the　luminescent　properties　of　the　LED　device.　©　2015,　Science　Press.　All　right　reserved.